>>530633930
>is there any way to make retroarch remember the shader I picked?
Yep, picrel. Global will apply the shader preset to all cores, Core will only apply to the current core you're using, and Game will apply only to the game.
>also, can I use different shaders per game?
Absolutely, this is where the Save Game Preset option shines. You can also toggle some of your shader presets by pressing the period key.